Active Directory Application Mode (ADAM) is an LDAP-compliant directory service.
ADAM has a simple install and runs as a service on Windows operating systems. It can be fully customized and distributed as an application component or used as a stand-alone LDAP directory. ADAM uses the same technologies found on Active Directory Domain Controllers (including replication and delegation features) and has its own administration and customization features. It can be run as a Windows server.
ADAM can be installed, as a free distribuable, on Windows XP, 2000, 2003, and 2008 operating systems. An improved version of ADAM is included as part of Windows Server 2003 R2 and Windows Server 2008 under the name Lightweight Directory Service (LDS).